Note 9 - Net Loss Per Share of Common Stock - Summary of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Net loss	$ (18,477)	$ (13,057)	$ (7,105)	$ (8,004)	$ (31,534)	$ (15,109)
Net loss per share - basic and diluted (in dollars per share)	$ (0.61)		$ (0.35)		$ (1.22)	$ (0.78)
Weighted-average shares used to compute basic and diluted net loss per share (in shares)	30,505		20,414		25,844	19,247